WO 95 15267 Stained, Glass Systems
WO 98 43832 Pearson
This invention relates generally to architectural building panels and more specifically to building panels that incorporate multiple pane sealed glazing units with decorative features.
Conventional curtain wall cladding systems are non-load bearing walls that are suspended in front of a main structural frame of a building. Typically, a curtain wall system consists of a rectangular grid of vertical and horizontal metal framing members with infill panels of clear vision glass and opaque insulating panel assemblies that can be clad with a metal, tile, stone or glass facing.
Particularly in cold weather climates, there are a number of performance drawbacks with these conventional curtain wall systems. There are four main issues:
1. Because of a metal grid framing system, there can be substantial conductive heat loss particularly through the framing system and at perimeter edges of glazing units and panel assemblies.
2. Because of a multi-component panel assembly, a jointing design for an air barrier and rain screen system can be very complex and prone to failure.
3. Particularly for elaborate heritage window designs, on-site installation can be very labor intensive.
4. Because of the need to insulate a panel wall assembly, potential rentable interior space is reduced.
In U.S. Pat. No. 5,494,715 issued to Glover, there is a description of various efforts that have been made in recent years to improve both energy efficiency and condensation resistance of multiple glazed sealed units. These improvements include: low-e coatings, argon or krypton gas fill, insulating spacing-and-desiccant systems for perimeter edge seals and narrow-width cavities (approximately xe2x85x9cxe2x80x3 spacing for argon gas filled units).
As also noted in U.S. Pat. No. 5,494,715, there is a growing consumer interest in heritage window features and these window features can include colonial style divided-lite windows, leaded or stained glass windows and decorative sun screens. These decorative features can be very labor intensive to produce and to simplify production, Glover describes how visual illusion of these features can be created by virtue of decorative stripe patterns that are applied to two or more glazing sheets of a multiple glazed unit. Because of potential durability problems, material of the stripe patterns must be non-outgassing and with high volume production methods, experience has shown that for typical coating materials, this is a very demanding technical requirement.
Various efforts have also been made to simulate the appearance of traditional building materials. U.S. Pat. No. 4,968,553,issued to Cesar, describes how a graphic laminate is created by heat laminating a printed sheet of extruded polyurethane between two plates of glass, using a conventional autoclave process. In WO 95/15267 issued to Stained Glass Systems, an alternative method for producing decorative glass panels is described by which ceramic decals with printed designs simulating marble or other materials are applied to a glass sheet which is then heated so that ceramic material of the decals is fused to the glass sheet. In producing large decorated glass panels, a series of ceramic transfers are placed side-by-side. However, because of a need for high accuracy, this process is very labor intensive and cannot be easily automated.
In WO 98/43832, issued to Pearson, automated equipment for applying ceramic decals is described wherein heat release decals on a decal carrier are laminated onto glass sheets. Unlike an automated decal stamp pad equipment developed by Service Engineers for Stained Glass Systems, (See Product Literature: Fully Automated Multi-Color Glass Decorative Machine Designed for In-line Production, Stained Glass Systems, September 1996), decals are applied through a roller press system where glass sheets continuously pass through a laminating station.
Although large sized panels can be produced by this method, individual large scale decals are conventionally printed and their manufacturing process is not suitable for production of one-off custom products.
DE-U-295 05 223.6 discloses a building door that has an insulating glazing unit mounted in a casement frame. The glazing unit has two spaced apart parallel co-extensive glazing sheets sealed together at their peripheries. The sheets define a transparent window area that is surrounded by registering frames formed of plastic or metal and bonded to outer sides of the two sheets. An area of a door between the peripheries and the attached frames surrounding the transparent area is covered on each of the glazing sheets by a layer of opaque material which can be provided by various methods.
The invention provides an architectural building panel in the form of a sealed glazed unit comprising: at least two spaced apart parallel coextensive glazing sheets; peripheral seals extending continuously between edges of the glazing sheets to define an insulating cavity between adjacent glazing sheets. Each of the glazing sheets has a transparent area, wherein the transparent areas of respective sheets are in alignment to define a window region, and also has surface area patterns on part of at least two surfaces of the glazing sheets. Opaque strip elements are located on surfaces of two of the glazing sheets, with the opaque strip elements surrounding the transparent area of an associated one of the glazing sheets, and wherein strip elements on different surfaces are in mutually aligned registration with each other and have a width extending parallel to the glazing sheet surfaces that is sufficient to create a visual illusion of a solid member within a cavity. The combination of the transparent areas and the surface area patterns simulates the appearance of a window incorporated within a building wall.
Between a window region and peripheries of the panel, the surface area patterns on the two glazing sheets preferably comprise overlapping patterns that collectively simulate the appearance of a traditional building material, with exterior glazing sheet patterns including transparent areas and adjacent interior glazing sheet patterns registering at least partially with the transparent areas of the exterior glazing sheet patterns.
The sealed glazed unit consists of two or three glazing sheets that define one or two glazing cavities that are preferably filled with argon gas for improved energy efficiency. Also to provide for improved energy efficiency, a low-e coating is preferably incorporated on at least one surface of the glazing cavities.
Strip patterns may preferably define window frames surrounding the transparent area, and around the frames surface area patterns may be designed to simulate almost any kind of surface finish, and in particular the appearance of traditional building materials such as bricks, stone, granite, marble and clay tile, and the like, including mortar joints and the like.
The surface area patterns can be provided in any suitable manner, e.g.: by use of ceramic frit materials that can be deposited on glass by virtue of heat transfer decals in roll or strip form; by printing patterns on flexible plastic film material laminated onto a cavity surface of one or more of the glazing sheets; or by printing patterns on flexible plastic film material from which surface area patterns can be transferred to a plastic coating on one or more of the glazing sheets by virtue of a dye sublimation process.
The opaque strip elements can similarly be provided in many ways, e.g.: by use of ceramic frit material; by printing on flexible plastic film material; by use of strips of flexible plastic sheet material adhered to glass by virtue of a pre-applied pressure sensitive adhesive on strips; or by use of shaped form members adhered to exterior surfaces of the glazing sheets. In the latter case, the shaped form members can be vacuum formed from plastic sheet material or may comprise hollow linear profiles. The shaped form members can be adhered to the glazing sheets by virtue of double sided adhesive foam tape or by other manners.
However provided, the opaque strip elements are preferably designed to have one side that is of a relatively light shade and an opposite side that is of relatively dark shade, and are attached to the glazing sheets in an orientation such that the side of the relatively dark shade is adjacent to the glazing cavity. This, in conjunction with relatively close spacing of the glazing sheets, creates an illusion that the opaque strip elements constitute solid window frame elements extending through the building panel.
Building panels as described herein are useful in many applications. One notable example is their potential for use in providing a curtain wall structure in multi-story buildings. In this application, a panel will be sized to span a distance between structural floors of a building. The glazing sheets will preferably be of heat strengthened or tempered glass. Also, it is advantageous for the exterior glass sheet of the building panel to be slightly enlarged, i.e. to have perimeter edges that extend slightly beyond edges of the other glazing sheet or sheets, thereby providing peripheral support flanges. Rigid channels can be adhered to the support flanges by virtue of silicone sealant, and these channels can suitably be fibreglass.